Abstract: It has been discovered that using n-butylmethyldimethoxysilane (BMDS) as an external electron donor for Ziegler-Natta catalysts can provide a catalyst system that may prepare polypropylene films with improved properties. The catalyst systems of the invention provide for controlled chain defects/defect distribution and thus a regulated microtacticity. Consequently, the curve of storage modulus (G?) v. temperature is shifted such that the film achieves the same storage modulus at a lower temperature enabling faster throughput of polypropylene film through a high-speed tenter.

Abstract: The invention is directed to a metallocene catalyst system and a process for preparing the system. The metallocene catalyst system comprises a support and metallocene bound substantially throughout the support. The selection of certain supports facilitates the production of metallocene catalyst systems having increased catalytic activity than previously recognized.

Abstract: Disclosed is a heterophasic polymer having a flowability over a broad range of xylene solubles content of the heterophasic polymer, a metallocene catalyst system (MCS) for producing such heterophasic polymer, and a method of producing such heterophasic polymer using the metallocene catalyst system. The MCS includes a support and a metallocene bound substantially throughout the support.

Abstract: Supported stereospecific catalysts and processes for the stereotactic propagation of a polymer chain derived from ethylenically unsaturated monomers such as the polymerization of propylene to produce syndiotactic polypropylene or isotactic polypropylene. The supported catalyst comprises a stereospecific metallocene catalyst component and a co-catalyst component comprising an alkylalumoxane. Both the metallocene catalyst component and the co-catalyst component are supported on a particulate polyamide support comprising spheroidical particles of a polyamide having an average diameter with the range of 5-60 microns, and a porosity permitting distribution of a portion of the co-catalyst within the pore volume of the polyamide particles while retaining a substantial portion on the surface of the particles. The polyamide support is characterized by relatively low surface area, specifically a surface area less than 20 square meters per gram.

Abstract: Polymerization processes in a bulk loop reactor are described herein. In particular, a method of contacting a flow of metallocene with a flow of propylene is provided. This method includes directing the flow of metallocene towards a junction, directing the flow of propylene towards the junction and maintaining a portion of the flow of metallocene separate from a portion of the flow propylene within a portion of the junction downstream of the flow of propylene into the junction. In another embodiment, a method of introducing a quantity of antifouling agent into a catalyst mixing system is provided. In this embodiment a portion of the antifouling agent is introduced at or downstream of a point of contact of a stream of propylene with a stream of catalyst. The antifouling agent may be a member, alone or in combination with other members, selected from Stadis 450 Conductivity Improver, Synperonic antifouling agent, and Pluronic antifouling agent.

Abstract: The present invention relates to propylene polymerization process in a bulk loop reactor, and particularly to propylene polymerization process for polymerizing commercial quantities of polypropylene in a bulk loop reactor by sequentially introducing Ziegler-Natta and metallocene catalyst systems into the bulk loop reactor.

Abstract: The present invention relates to propylene polymerization process in a bulk loop reactor, and particularly to propylene polymerization process for polymerizing commercial quantities of polypropylene in a bulk loop reactor by sequentially introducing Ziegler-Natta and metallocene catalyst systems into the bulk loop reactor. In one embodiment, separate catalyst mixing systems are used to introduce a quantity of metallocene catalyst and Ziegler-Natta catalyst into the bulk loop reactor. The frequency rate at which the quantity of metallocene catalyst is introduced into the bulk loop reactor may be higher than the frequency rate at which the quantity of Ziegler-Natta catalyst is introduced.

Abstract: Supported stereospecific catalysts and processes for the stereotactic propagation of a polymer chain derived from ethylenically unsaturated monomers such as the polymerization of propylene to produce syndiotactic polypropylene or isotactic polypropylene. The supported catalyst comprises a stereospecific metallocene catalyst component and a co-catalyst component comprising an alkylalumoxane. Both the metallocene catalyst component and the co-catalyst component are supported on a particulate polyamide support comprising spheroidical particles of a polyamide having an average diameter with the range of 5-60 microns, and a porosity permitting distribution of a portion of the co-catalyst within the pore volume of the polyamide particles while retaining a substantial portion on the surface of the particles. The polyamide support is characterized by relatively low surface area, specifically a surface area less than 20 square meters per gram.

Abstract: The invention is directed to a metallocene catalyst system and a process for preparing the system. The metallocene catalyst system comprises a support and metallocene bound substantially throughout the support. The selection of certain supports facilitates the production of metallocene catalyst systems having increased catalytic activity than previously recognized.

Abstract: The present invention relates to propylene polymerization process in a bulk loop reactor, and particularly to propylene polymerization process for polymerizing commercial quantities of polypropylene in a bulk loop reactor by sequentially introducing Ziegler-Natta and metallocene catalyst systems into the bulk loop reactor. In one embodiment, separate catalyst mixing systems are used to introduce a quantity of metallocene catalyst and Ziegler-Natta catalyst into the bulk loop reactor. The frequency rate at which the quantity of metallocene catalyst is introduced into the bulk loop reactor may be higher than the frequency rate at which the quantity of Ziegler-Natta catalyst is introduced.

Abstract: A metal sheave is turned on a lathe to remove worn flange and groove portions to provide three roughened cylindrical surfaces of progressively greater diameter about which a peripheral rim body of polyurethane is cast in an encircling mold and permitted to cure; the sheave is then turned on a lathe to shape the polyurethane to provide peripheral flanges and a groove therebetween.

Abstract: A low-friction pulley member formed of high-density polyethylene having a molecular weight of between two and five million is mounted for rotation on a stainless steel supporting shaft including a head flange received in a cylindrical recess in one face of the pulley member and a retainer groove for a snap-ring retainer to provide a durable, low-friction and corrosion resistant pulley unit.

Abstract: A conveyor belt is fabricated by unrolling first and second webs of uncured rubber between which plastic-jacketed reinforcing cable tendons are fed to provide an uncured sandwich array which is then fed into a vulcanizing unit which is then operated to provide a cured belt section. The steps are successively repeated with mechanical cable tenden splices being made during the vulcanizing operation with the different splice junctions of each cable tendon being spaced a maximum distance from the next adjacent splice junction of another cable tendon along the entire length of the belt member being formed.